If you don't already have that line in /etc/resolv.conf, you need to add it in order to get internet working... In order to get my wifi card up and running, I needed to add that line, and run this script on startup:
echo "Setting encryption key..."
iwconfig ath0 key encryption-key-goes-here
# My card (ath0) has a static ip (192.168.0.192) assigned to it by the router, so no DHCP.
# If you need DHCP, run dhcpcd first, and remove the ip from ifconfig
echo "Setting IP address and bringing up interface..."
ifconfig ath0 192.168.0.192 up
echo "Creating default route and gateway..."
route add default gw 192.168.0.1 ath0
And that's all I had to do... you REALLY need that line in /etc/resolv.conf, though, if you don't already have it.
Apart from that, I'm out of ideas. Try the resolv.conf thing if you haven't already.